The present invention relates to a sound system and more particularly to a sound system for use with a television receiver.
In loudspeaker systems, and particularly speaker systems for reproducing bass, there is a substantial problem with unwanted resonances and with the undesirable vibrations of cabinet structures in response to signals at various frequencies. These vibrations are particularly a problem for large enclosure walls which have no intermediate support between their secured edges. In order to prevent such vibrations, enclosure components have to be more sturdy and/or heavy enough to either resist such vibrations, or to bring the natural resonant frequencies of the various cabinet structures below that of the signal frequencies. If vibration can be reduced without resort to more sturdy or heavy parts, the parts can be cost reduced, and the cost of shipping due to a reduced weight can be realized.
It is desirable in a loudspeaker enclosure that parallel surfaces be reduced to a minimum since parallel surfaces can set up resonant/anti-resonant frequencies within the cabinet (acoustic standing waves) and cause unwanted peaks and/or cancellations in the idealized flat frequency response. Additionally, such resonant frequencies set up vibration modes as discussed above, which can cause extraneous sounds, such as buzz.
Recently, music systems have been designed that are known as bandpass low frequency enclosures. These enclosures acoustically filter out much of the harmonic distortion sound components produced by woofer loudspeakers at high sound levels. These arrangements use a subchamber which has a port tube coupling the subchamber to the outside of the enclosure. Such arrangements are shown in U.S. Pat. Nos. 4,549,631 of Bose, 5,033,577 of Veranth, and 5,092,424 of Schreiber et al.